downtube42

I just built up a bike with a Shutter Precision dynamo for lighting. This is my third SP build since 2013, and the first two have been flawless.

This new build has a noticable vibration and low growling noise when the lights are on. SP says I can do a warranty return. That's great, but it means unbuilding/rebuilding the wheel and going without dynamo lighting for unknown number of weeks. Shipping sucks right now. Just as we head into the time of year when I need lights.

I was hoping they would say it's normal for a new hub and will improve, but that wasn't suggested.

Does anyone have experience with this behavior on SP dynamos?

unterhausen

It sounds like it might be in the normal range depending on the fork and light. If you have previously used the same bike with the same light then it's cause for concern.

I had a lot more vibration issues when I was using Supernova lights.

I don't think it will get better though, unless the bearings have some reason to wear in. But that generally isn't something that happens.

Tourist in MSN

If this SP has characteristics that are quite different than two other SP hubs that you are familiar with,sounds to me like you already know the answer. Bummer. I have two SP hubs, neither of which make any noise that I can think of.

Do you still have one or both of the other SP wheels you built, and are they the same size wheel? Can you put one of those older wheels on the bike to see if this new wheel clearly is different in vibration and noise than an older hub?

I can't think of any reason that an SP hub would improve with use over time. I do not think there are any seals other than the cartridge bearing seals that could benefit from wearing in.

I can think of one other test, with the hub disconnected from the wiring and the wheel in a fork or truing stand with the skewer tightened as normal, it is my experience that a dynohub wheel when spun by hand will slow to a stop a bit quicker than a non-dyno hub wheel. If this new wheel slows to a stop much faster than another SP hub wheel with the same rotating mass (same weight rim and tire), then there is something causing more drag in it which does not sound good.

Good luck.

Moe Zhoost

When you say that the others are flawless, are you talking about trying all three on the same bike? If not, then maybe the vibration is related to the bike. I can certainly imagine that on some forks, the hub could set up a constructive mechanical resonance that could be disturbing.

I only have one SP dyno, but have used Shimano and S-A dynos and they all seem to have a noticeable hum and vibration at certain speeds. Neither of these are to the level of concern, I just figured they just come with the territory.

veganbikes

I haven't had issue on my SP hub at all. Nor my SON hub. It sounds like this is a warranty issue. Yeah it sucks but they are getting you a new one and if you had the wheel built up by someone see if they will cover the cost of the build or something. Some companies will do that.

I would check and make sure the vibration isn't from something else and everything is properly tightened and not overtightened and everything is just so.

downtube42

Weird experiment results warrant further investigation. For the moment I'm just experimenting with one old dynohub and the new one.

Baseline testing: Spinning the new hub in the new bike with lights on, there's what I'll describe as a ticking sound. At speed it becomes almost a growl, but on the stand it's distinctive ticks. With the lights unplugged at the dynohub, there is no sound. With the lights plugged in but turned off, there is no sound. Same experiment on the old bike yields no such sound.

I put the new (noisy hub) wheel on the older bike and gave it a spin: no sound! The lights were on and working. So that suggests the problem is something with the new bike.

To complete the story, I put the old wheel on the new bike and gave it a spin: also no sound! Lights were on and working. Unexpected, given the first result.

Putting the new wheel back on the new bike and giving it a spin, again there is the ticking sound.

Now on to electrical tests. I unplugged the tail-light and gave it a spin: sound. I reversed the polarity at the dynohub (which should not matter), and also sound.

For the moment I've retreated from the garage.

Tourist in MSN

I have run out of suggestions.

Moe Zhoost

Probably a good idea to stop and ponder a bit.

Suggested next step: Perhaps the ticking is a small break in the + wire causing a short. You can test this by bypassing the existing wiring on the new bike by wiring in an independent length of wire. If no ticking, then re-run new wire.

Also, don't rule out that there is an issue with the light. Isolate it from the bike and test the dyno wheel.

downtube42

Yeah, wiring at the dyno connector is slightly suspect, since it would be disturbed during the wheel switch.

My other thought is my spin test could have been inconsistent, though the difference between sounds and no sound was stark.

Tourist in MSN

I said above that I ran out of suggestions, but since then I came up with one more test - but I suspect you don't have the stuff for this test. But I am mentioning it just in case you do and want to try one more test. That said, if it was me, I would already have asked for a warranty exchange and I would have asked for them to send the hub first so I could rebuild the wheel in one sitting.

If I was doing a comparison between two wheels and I suspected one was suspect, I would try to figure out if one dynohub has less output than the other, I would wire my Sinewave Revolution to the dynohub (that is a device that takes dynohub output and converts it to USB power) and I would plug that into a power bank, with a current and voltage meter in between so I could measure USB output at a couple of different speeds on the bike with each wheel. The Sinewave lacks a small pass through cache battery, the lack of such a batter is necessary for such a test. A battery would complicate things.

Then ride with that wheel at a constant speed for maybe a half minute to take voltage and amperage readings while the charger is charging the power bank. I would do a couple speeds, say 10 mph and 13 mph, those are speeds well below the max output of the Sinewave. And do that test with each wheel. I live close to a flat bike path with enough distance I could do such a test within sight of my condo.

A better way to do such a test would be use a multimeter to measure dynohub output across a resister. That skips the USB converter that I described above, but I do not have a good resister with the right resistance that could take that much load, thus I would try the USB thing that I described above since I have the equipment for that.

Then if the new noisy hub puts out measurably less power, for sure you have a reason to claim a warranty exchange.

downtube42

Good point, I had not thought about inspecting the power output. That has me looking at cheap oscilloscopes, like the DSO138 kits. https://www.amazon.com/dp/B00WAQGGZA..._DRMDFbSAAYD7B

Tourist in MSN

I am clueless on oscilloscopes.

As I mentioned above, since I have the means to measure USB output, that is what I would have done with my Sinewave USB charger that takes hub output and converts that to USB power.

When I said I would measure current and voltage, i would use one of these (transparant is much easier to read outside than the blue but both are impossible to read in direct sunlight):
https://www.ebay.com/itm/B-Charger-D...e/154040938333

Or one of these:
https://www.ebay.com/itm/USB-Charger...r/324306204453

Shipping from Asia usually takes over a month.

But if you know how to use an oscilloscope, great, because I do not.

unterhausen

could be wrong, but I doubt that a oscope will help much unless you get a $20000 version that captures glitches. And I also assume you would disturb whatever it is causing the problem

steelbikeguy

scopes have really come down in price in the last 5 or 10 years!
I just got a little Rigol 4 channel, 100MHz scope earlier this year for $500! It's got a bunch of trigger modes to capture weird transients. Twenty years ago, this sort of functionality would have cost as much as a compact car.

but... I'd recommend falling back on a basic rule of troubleshooting... swap out each component until the problem goes away. Has the OP tried swapping the headlight for a different headlight? A 12 ohm, 3 watt resistor would work too, since that's basically what the old incandescent bulbs were.

Steve in Peoria
(those little 200kHz scope gadgets are interesting, but very limited. Might be good enough if you really knew what you were doing)

downtube42

I swapped the generator hub wheel with one from another bike, and the problem went away. I could have stopped there believing I'd found the problem. But then I put the suspect hub wheel on the other bike, and it did not exhibit the problem. That bike has a different brand of headlight and taillight.
​​​​​​I am building a test harness, to eliminate wiring issues, and for conducting other tests.

steelbikeguy

The good news is that you are making progress and have gained some insights into the details.
Another good aspect is that nothing has gotten broken in the process, which does sometimes happen when troubleshooting by swapping parts. (I'm speaking from a fair bit of personal experience!)

One of the frustrating aspects of troubleshooting is that it is possible that the mere act of removing and reinstalling a part can change the problem or symptoms. In electronics, this is often the result of a dodgy electrical connection that improves when disconnected and reconnected. This can be due to corrosion or crud on the electrical contacts. If the frame is used as a conductor, this could easily be the case. I'm not a fan of this practice, since electrical connections should be resistant to corrosion. Most bike frames don't fit this description.
In your case, I'd suggest putting the original dynamo back in the original bike and verifying that the problem still exists. If the problem is gone, then there may be an issue with the electrical connections.

Steve in Peoria

Tourist in MSN

I doubt if electrical connections could cause clicking or growling sounds with vibration.

SP hubs are not grounded to the fork like Shimano hubs.

downtube42

OP back to wrap it up. I finally just gave up and sent the hub to SP. They fixed it and refunded all shipping charges.

The major downside was having to rebuild the wheel, but it runs smooth as silk now.

Tourist in MSN

Thanks for posting. On this forum I have seen comments on two SP hubs with bearing failures, yours is the only other one I have seen mentioned. Not sure how many are out there, but I think there are a lot of SP hubs in use. I bought a third one a couple months ago.

sweeks

I'm not sure if you're referring to lots of SP hubs out there, or lots of failing SP hubs out there.
I have an SP hub on my daily folding commuter; the hub has almost 9,000 miles on it and is working fine. I re-built the wheel at 8,000 miles and considered whether I should have the hub's bearings replaced first. Finally, I decided to take the risk, since I can always take the hub out and re-install it after service. So far, so good.
FWIW, I'm a heavier rider (~220 pounds with backpack), and Chicago streets aren't terribly smooth.
I also have an SP hub built into a wheel for my non-folding road bike, but it only has a few hundred miles on it. My impression of these hubs is that they are well-made, and based on the performance of the one hub they seem durable as well. Plus they are nice-looking!

Got this hub on sale. Maybe because it's red? ;-)

unterhausen

I have 2, one on my mountain bike and one on my gravel bike. So they see rough duty. There are more failures reported than I would like to see, but I'm sure it's a very small number overall.
It's not like the early SON hubs where everyone eventually had a water intrusion problem.

Tourist in MSN

I meant a lot of SP hubs in use, I edited my previous text to clarify. Thanks for pointing out the ambiguity.

steelbikeguy

well, not everyone!
This one probably has 40,000 miles on it, although I did send it back to Peter for bearing service somewhere around 20,000 miles. It was fine, but I was unlacing the wheel to change rims, so I figured it was a good time for it. It has seen plenty of rain and snow over the 20+ years that I've had it.



Steve in Peoria

noglider 

Beautiful bike and picture, @steelbikeguy.